Well, within 5 minutes of posting my previous comment, I devised what may be potential workaround. It works for me, and I think is okay as a short term strategy. But as I am fairly new to Libreoffice, I’d certainly like to know how to do this in a more permanent, or more effective manner. To overcome the continuous document resizing as new toolbars appeared, I simply undocked the offending toolbar from the top (or side) of the document screen, and placed it as a floating tool bar over the document window. Now when I select an object, such as a picture, the “Frame” toolbar appears as a floating toolbar, in the last position it was used, nicely placed out of the way of my document. But, the document no longer shifts and things appear to work as normal. I do have the luxury of a large monitor, so this would still be annoying for smaller screens. However, for now, I can live until I find a better solution.
EDIT: be sure to ‘save’ your document after each toolbar change, or the repositioning behaviour reverts to it’s old ways.